JPH08204072A - Device for cooling electronic parts - Google Patents

Abstract

PURPOSE: To enable safe use of an electronic apparatus even under the poor environment like a factory where a large amount of dust and oil mist exist in the open air by cooling electronic parts through thermal conduction without using a cooling fin. CONSTITUTION: A through hole 3 is provided in the area of a circuit board 1 where an electronic part 4 which requires cooling is mounted, and a thermal conductive piece 2 integrally forming a holding part which is in the surface- contact with the bottom part of an electronic part and heat radiating part provided at the rear side of the circuit board is provided through the through hole. Heat of the electronic part is transmitted to the thermal conductive piece and is then transmitted to the heat radiating plate 7 through an elastic thermal conductive sheet 6 from the thermal conductive piece. Thereby, electronic part can be cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for electronic parts such as ICs mounted on a circuit board, and more particularly to a cooling device suitable for cooling electronic parts by heat conduction.

[0002]

2. Description of the Related Art In order to cool electronic components mounted on a circuit board such as a personal computer or a workstation, an electronic component such as an IC, which generates a large amount of heat, can be made of a material having a relatively high thermal conductivity such as aluminum. A forced air cooling system is adopted in which a heat radiating plate is attached and the warm air inside the housing is discharged to the outside by a fan or the like, and electronic components can be efficiently cooled by a relatively simple means.

[0003]

Although electronic devices such as computers have become widespread in factories, electronic devices generally referred to as OA devices such as personal computers and workstations described above are used in environments with little dust. It is made for use. Therefore, if you use the above equipment that uses a fan to perform forced air cooling in a factory where a large amount of dust or oil mist is present in the air, there is a possibility of causing failures such as short circuits, poor insulation, poor contact, and corrosion. is there. Therefore, when using OA equipment in such an environment, a filter is installed in the part that sucks the outside air into the housing, and the air inside the housing and the air outside the housing do not flow in and out, and only heat is exhausted to the outside. A method of using a heat exchanger for cooling or a cooling method using an electronic cooling device utilizing the Peltier effect is used.

However, in order to obtain the required cooling capacity in the above-mentioned method, the apparatus becomes large in size, heavy in weight and complicated, and the cost is often increased. Further, if fins for direct heat dissipation are directly attached to each electronic component, it is difficult to achieve high density packaging spatially.

The present invention has been made in view of such circumstances, and an object thereof is to use a fan without using even in a bad environment in which a large amount of dust and oil mist exist in the air. An object of the present invention is to provide an electronic component cooling device capable of safely cooling electronic components.

[0007]

In order to achieve the above object, the present invention provides a circuit board having a through hole at a position where an electronic component is mounted, a penetrating portion penetrating the through hole, and the electronic component. A heat conducting piece integrally formed with a holding portion that comes into surface contact with the bottom of the substrate and a heat radiating surface portion provided on the back side of the circuit board; and a heat radiating plate that comes into contact with the heat conducting piece. . It is also possible to provide a heat conductive sheet having good heat conductivity and elasticity between the heat conductive piece and the heat dissipation plate. Further, the heat dissipation plate can be configured by a part or all of the housing.

[0008]

The heat conducting piece that comes into contact with the bottom of an electronic component such as an IC that generates a relatively large amount of heat absorbs the heat of the electronic component from the bottom. The heat propagates through the heat conducting piece, passes through through holes provided in the circuit board, and reaches the back side of the circuit board. Directly from there,
Alternatively, it is transmitted to the heat radiating plate or the housing via a heat conductive sheet or the like. This allows the electronic components to be cooled.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a circuit board according to the present invention. (A) is the front surface of the circuit board 1, (b) is the back surface,
(C) shows a cross section of the circuit board 1. Further, (d) shows an example in which electronic parts are mounted on (c). A through hole 3 is provided at a location where an electronic component such as an IC on the circuit board 1 made of an insulating material such as glass epoxy and having a relatively large amount of heat generation and requiring cooling is arranged. The size and number of the through holes are not particularly limited, and as shown in FIG. 1, a large number of holes may be formed with the same diameter as the holes into which the legs of electronic components such as ICs are inserted. A heat conduction piece 2 is provided which penetrates the through hole 3 and has a surface for heat conduction on both the front surface and the back surface of the circuit board 1. The material of the heat conducting piece 2 is preferably a good heat conducting material such as copper or aluminum. If the material of the heat conducting piece 2 is copper, the material of the circuit pattern of the circuit board is generally copper, so that the heat conducting piece 2 can be drawn as one of the circuit patterns. By doing so, the circuit board can be manufactured in almost the same manner as the conventional circuit board, and the increase in manufacturing cost can be suppressed. Also, the heat conduction piece 2
The manufacturing method is not limited to this, and it is also possible to fit the separately manufactured metal piece to the circuit board 1 to form the heat conduction piece 2.

Next, in FIG. 1D, when the lead wire 5 of the electronic component 4 is fixed to the circuit board 1 by soldering, the bottom of the electronic component 4 comes into contact with the heat conducting piece 2 at the same time. In addition, if a silicone resin or the like is filled between the bottom of the electronic component 4 and the heat conducting piece 2, a small gap is filled and heat conduction can be performed more reliably.

Next, how to cool the electronic components mounted on the circuit board 1 will be described with reference to FIG. When the electronic component 4 mounted on the circuit board 1 generates heat, the amount of heat generated by the electronic component 4 is in contact with the bottom of the electronic component 4.
Conveyed to. Next, the amount of heat is transmitted through the inside of the heat conducting piece 2 and reaches the back surface of the circuit board 1. Next, the amount of heat is transmitted to the heat conductive sheet 6 in contact with the heat conductive piece 2, and further to the heat dissipation plate 7 in contact with the heat conductive sheet 6. The amount of heat transferred to the heat radiating plate 7 in this way is transferred to the surrounding air or is radiated. It is also effective to increase the cooling capacity by using a conventional technique such as applying a black coating to the heat dissipation plate 7 to increase the radiation efficiency or providing a large number of blade shapes to increase the surface area.

Since lead wires of electronic components and the like are soldered on the back surface of the circuit board 1, there is unevenness, and in order to fill the unevenness and make sure contact with the heat conducting piece 2 to transfer the amount of heat to the heat dissipation plate 7. In addition, the heat conductive sheet is effective. Further, since the heat dissipation plate 7 is mainly made of metal, it cannot be brought into direct contact with the back surface of the circuit board 1. However, when the heat conduction sheet 6 is made of an insulating material such as silicone resin, it is electrically insulated. The amount of heat is indirectly maintained from the heat conducting piece 2 to the heat sink 7
I can tell you.

In the cooling device for electronic parts described above, an example in which the heat radiating plate 7 is used as it is as a part of the housing for housing the electronic equipment is shown in FIGS. 3 and 4. The circuit board 1 is disposed inside the back surface of the housing 8, and the back surface of the housing is used as it is as the heat dissipation plate 7. Further, as shown in FIG. 4, a large number of wing shapes are provided on the back surface of the housing to increase the surface area, so that the cooling capacity can be enhanced.

[0014]

As described above, according to the present invention, the heat of the electronic component is radiated to the outside of the housing by utilizing the heat conduction, so that the housing can be of a hermetically sealed type, and dust, oil mist, and oil smoke are contained in the air. It is possible to safely and efficiently cool electronic components even in a poor environment where, for example, the above conditions exist. In addition, compared to conventional electronic devices that use a fan for cooling, noise is reduced and power consumption can be reduced. Further, since the housing can be hermetically sealed, there is also an effect that it is possible to use an electronic device in which electronic components such as ICs are mounted at high density even under a special environment such as underwater or earth and sand.

Further, in the method for cooling an electronic component according to the present invention, since cooling is performed by heat conduction, the cooling capacity can be calculated relatively easily as compared with the case of forced air cooling, and the heat dissipation in the circuit board design can be improved. It also has an effect that simulation can be easily performed.

[Brief description of drawings]

FIG. 1 is a circuit board provided with a heat conducting piece according to the present invention.

FIG. 2 is a sectional view of a circuit board according to the present invention.

FIG. 3 is an electronic device including a cooling device for an electronic component according to the present invention.

FIG. 4 is an electronic device including a cooling device for electronic components according to the present invention.

[Explanation of symbols]

 1 circuit board 2 heat conduction piece 3 through hole 4 electronic component 5 electronic component lead wire 6 heat conduction sheet 7 heat sink 8 housing

Claims (3)

[Claims] 1. A circuit board provided with a through hole at a position where an electronic component is mounted, a penetrating portion that penetrates the through hole, a holding portion that makes surface contact with a bottom portion of the electronic component, and a circuit board rear side. A cooling device for an electronic component, comprising: a heat conducting piece integrally formed with a heat radiating surface portion; and a heat radiating plate in contact with the heat conducting piece. 2. The cooling device for electronic parts according to claim 1, further comprising a heat conductive sheet having good heat conductivity and elasticity between the heat conductive piece and the heat dissipation plate. 3. The cooling device for an electronic component according to claim 1, wherein the heat dissipation plate is a part or all of a housing.